This invention pertains to the art of reels, cores or the like for holding tubing or wire and more particularly to an expandable, collapsible and removable core for large rolls of tubing; such as the corrugated plastic tubing used in the drainage tubing industry. However, it will be appreciated to those skilled in the art that the invention could be readily adapted for other uses or used in other environments as, for example, where similar reel devices are employed for the holding of other materials.
Conventionally, a normal roll of large tubing such as four inch corrugated tubing includes two hundred fifty feet of tubing. In recent years, the drainage contracting industry has tended towards using very large rolls of tubing, such as twenty five hundred to five thousand foot rolls, to eliminate the inefficiencies of handling smaller coils during transport and stringing operations. The ultimate size of these large rolls is limited only by the bulk and weight that can be handled by machinery and supported by existing ground conditions at field installations.
One present method used to handle and hold large rolls is to construct huge steel reels on which the tubing is wrapped in the manufacture's plant. The large reel with the tubing wrapped upon it is treated as a unit for shipping and stringing operations. Once the tubing is used, the steel reels must be retrieved and returned to the plant, where a large inventory must be maintained for production. Also, the size and weight of these large tubing and reel units is such that only excellent ground conditions will permit their use in the field or the units may become bogged down or stuck. This type of unit is shown in Drainage Contractor magazine, Vol. 4, No. 1 at page 90 (1978).
Another typical prior art reel is comprised of a piece of eighteen inch steel corrugated pipe for use as the core of a large roll of corrugated plastic tubing. Again, a disadvantage of this device is that it must be retrieved by the manufacturer once the roll is used. Also, the ends of the reels must be reinforced to protect them from damages incurred from the heavy machinery which must necessarily be used for their handling. In addition, hooks must be installed on the pipe to use as an attachment ring for restraining wires for the rolls of tubing. This device is further disclosed in Drainage Contractor, Vol. 5, No. 1, at pages 12-13 (1979).
The present invention contemplates a new and improved device which overcomes all of the above referred to problems and others to provide a new removable core which is simple in design, economical to manufacture, readily adaptable to a plurality of uses with tubing, wire, or the like having a variety of dimensional characteristics, easy to install, easy to remove and which provides improved ease of transportation and installation.